Gas-operated pistol



Sept. 7, 1965 B. G. SHEPHERD GAS-OPERATED PISTOL 2 Sheets-Sheet 1 FiledMarch 22, 1963 w om ow Mm m ow mw ww INVENTOR.

BOB e. SHEPHERD A TTORNEYS S t, 7, 19 5 B. s. SHEPHERD 1 GAS-OPERATEDPISTOL Filed March 22, 1963 2 Sheets-Sheet 2 iuuUUUG. UOUOOUOOL\\ FIGZFIG

INVENTOR.

805 G. SHEPHERD BY MM wxuafam A TTORNEYj United States Patent 3,204,625GAS-UPEPATEE PKSTUL Bob G. Shepherd, 843 Shull St West Columbia, SKI.Filed Mar. 22, 1963, Ser. No. 267,395 6 Claims. (Cl. 124-41) Aninvention related generally to a gas-operated pistol and moreparticularly to an improved BB pistol powered by a C0 capsule.

Pneumatically powered guns or pump guns are well known in the prior artand have been used for years as target practice devices and sportsweapons for hunting small game. A more recent development in this classof guns has been realized by the inclusion of a pressurized gas capsulesuch as the widely used CO capsule as a power source in the gun, bothfor providing a source of power for the projectile and, in some cases,as a motivating force for re-cocking the gun between firings.

The inclusion of CO or like compressed gases as an energy source in apneumatic gun has induced difficulties unknown in the earlier class ofguns such as the tendency of the gun valves to freeze due to the lowtemperature of the gas after expansion from the compressed state. Also,as stated above, some of the guns in use at present utilize a portion ofthe pressurized gas for re-cocking the gun between shots. This, ofcourse, results in a more rapid exhaustion of the contents of thepressurized capsule and resulting in a smaller number of shots percapsule. Some other guns in use at present, which do not utilize thepressure source as a cocking means, require that the gun be cocked byhand between each firing thereof.

The invention relates to the gas capsule type of pneumatic gun and hasas an object the provision of an improved and simplified mechanism forproviding semi-automatic operation of the gun without utilizing thepressure source for re-cocking the gun between shots. The inven-' tionalso has as an object the provision of a simple, easily fabricated andreliable mechanism for providing a semiautomatic gas-operated gun. Afurther object of this invention is the provision of a new and improvedinertiaoperated valve which is simple, inexpensive, and reliable andwhich is not susceptible to jamming or freezing in the presence of thelow temperatures generated by expanding gas. It is still another objectof the invention to provide a gas-operated gun in which a realisticrecoil impulse, simulating an explosive propellent gun, is provided byexpanding gas.

Other objects and many of the attendant advantages of this inventionwill be readily appreciated as the same becomes better understood byreference to the following detailed description when considered inconnection with the accompanying drawings in which like referencenumbers designate like parts throughout the figures thereof and wherein:

FIG. 1 is a side elevational View in section of a pistol embodying theelements of this invention prior to actuation of the mechanism forfiring a projectile therefrom;

FIG. 2 is a fragmentary view of the device of FIG. 1 showing themechanism in an intermediate state immediately prior to firing thereof;

FIG. 3 is a view of FIG. 2 showing the disposition of the mechanismimmediately preceding the instant firing of a projectile therefrom;

FIG. 4 is an enlarged sectional view of the valve position of the deviceat the instant of firing;

FIG. 5 is a perspective view of the device of FIG. 1 partly broken away;

FIG. 6 is a fragmentary sectional view of the device of FIG. 1 showingthe operation of an alternative portion .of the device.

In general the invention provides a barrel slidably "Ice mounted in theframe of the gun around the rear portion of which a Weighted hammerelement is mounted, the barrel and hammer assembly being spring biasedrearwardly and abutting a longitudinally opening valve. This valve isbiased closed in a forward direction against the bias of the barrel andhammer assembly by the pressure in the system. Actuation of the deviceis accomplished through a trigger and sear mechanism which, by utilization of the force expended in pulling the trigger, moves the barrel andhammer assembly forward. The geometry of the trigger and sear is suchthat the hammer is automatically released at a forward point of travelallowing the assembly to impact against the closed valve system. Theimpact of the assembly momentarily overcomes the pressure-biasing forceof the valve and allows a burst of pressure from a compressed gascartridge located there- .behind to be injected into the barrel of thegun providing the motivating force for a projectile located therein.This impact also provides a recoil-like kick in the gun resulting in arealistic simulation of a powder-type gun.

Referring now to the drawings for a more complete description of theinvention, the figures show the stepwise operation of a preferredembodiment of the invention.

The complete assembly is shown in FIG. 1 and cornprises a housing showngenerally at 2 in which is slidably mounted a barrel 4 having a hammer 6fixedly attached to the rear portion thereof. A valve assembly showngenerally at 3 is disposed behind the barrel and hammer assembly andprovides a sealing means between expansion chamber 10 and barrel 4. Abore 12 provides a passageway between the expansion chamber and capsulereceptacle chamber 14. A hollow needle 16 is coaxially mounted in bore12 and serves to puncture compressed gas capsule 20 when it is suitablyinserted therein. The hollow bore of the needle provides a passagewayfor the contents of the capsule to chamber it). 0 ring 18 provides aseal around the mouth of capsule 20 to prevent escape of gas therefrom.As shown in the drawings, receptacle 14 is preferably disposed in handle22 of housing 2. Closure member 24 is pivotally connected to the base ofhandle 22 and is preferably shaped as a cross-sectional segment of thehandle. Member 24 is provided with threaded bore 26 through whichthreaded shaft 28 is disposed. Shaft 28 is provided with a concave base3.6 which mates with the usually spherical base of capsule 2t). Shaft 28is connected at the other end thereof to butt member 32, which, in asimilar fashion to member 24, is formed as a cross-sectional segment ofhandle 22.

The operation of the closure member as thus far described isaccomplished by the pivoting of members 24 and 32 so as to expose thebase of chamber 14-, inserting capsule 20 into the chamber seal endfirst, followed by realignment of members 24 and 32. Member 32 is thenrotated with respect to member 24 causing threaded shaft 28 to engagethe base of capsule 2t), forcing the seal portion of the capsule againstneedle 16 ultimately resulting in rupture of the seal portion of thecapsule and communication of compressed gas to expansion chamber 10.

Referring now to the barrel portion of the structure, barrel 4 andhammer 16 are mounted within tube 34 which in turn is fixedly mountedwithin housing 2 as shown. Annular ring 36 is threaded in the mouth oftube 34 and serves to provide a closure for that portion of the tube anda slidable forward mount for barrel 4. Helical spring 38 is mountedbetween ring 36 and the forward face of hammer 6 to bias the barrel andhammer assembly in a rearward direction against valve assembly 8. Thethreaded mounting of ring 36 provides means to adjust the compression inspring 38. Trigger 4t) is pivotally mounted in housing 2 in the usualmanner and is pivotally connected through arm 42 to sear 44. The triggerand n =3) sear assembly are biased in a forward and rearward directionrespectively by helical spring 46. The forward end of sear 44 engagesnotch 48 in hammer 6.

In the operation of the trigger portion of the device, trigger 40 issqueezed in the usual manner causing arm 4-2 to move forward in anarcuate manner. This displaces sear 44 forwardly against the tension ofspring 46 and causes hammer 6 and barrel 4 to move forward in tube 34against the compressive resistance of spring 38. As trigger 4% issqueezed rearwardly, faces 52 and 54 of the trigger and searrespectively converge on one another due to the pivotal connection oftheir respective members (FIGS. 2 and 3). When faces 52 and 54 engage,further motion of trigger 40 in a rearward direction causes the end ofsear 44 engaging notch 48 to move in a downward direction releasinghammer 6 and barrel 4. Upon release of the hammer and barrel assembly,spring 38 forces the assembly rearwardly causing it to impact with valveassembly 8 as shown in FIG. 3.

Referring now more specifically to valve assembly 8, this is comprisedof cylindrical seat 56 slidably disposed in expansion chamber 10,annular seal member 58 coaxially disposed at the mouth of the expansionchamber, Washer 66 coaxially disposed forward of the seal member, andvalve stem generally shown at 62. Referring more particularly to FIG. 4,the valve stem is provided with an annular shoulder 64 and a tubularportion 66, the tubular portion extending coaxially through seal andWasher 60 in a rearwardly direction and, in a forwardly direction beingtelescopically disposed in the interior of barrel 4. An enlarged portion68 is disposed at the forward end of tubular portion 66 in slidingcontact with the interior of hammer 6. Helical compression spring 70 isdisposed in expansion chamber and serves to provide a partial bias ofseat member 56 forwardly against the rearward force of spring 50, insealing relationship to seal 58. The primary biasing force, however, isprovided by the pressure from capsule 20 in chamber 10. The variouscomponents are disposed so that shoulder 64 is held in spacedrelationship to washer 60 as shown. Seat 56 is provided with recessedportion 72 in the forward face thereof. Tube 66 is also provided withradially extending bores 74 disposed to communicate the interior of thetube with recess 72.

Referring again to FIG. 1, tubular shot chamber 76 is disposed along thetop of housing 2 in parallel relationship with tube 34. The shot chamberis provided with a closed forward end. A rear closure member, such, forexample, as simulated hammer 78, is pivotally mounted on housing 2 andspring loaded in the closed condition as shown. Spherical shots 80 areplaced in shot chamber 76 by insertion through the rear end of the shotchamber with hammer 73 held open against the biasing spring. Shotchamber 76 is provided with aperture 82 in the lower portion thereof, aportion of which coincides with radially disposed bore 34 through thewall of hammer 6 when the hammer is in a rearward position. Theabove-mentioned aperture and bores also are aligned with the enlargedportion 63 of valve stem 62 when the hammer and barrel assembly is inits relaxed rearward position. The enlarged portion is formed tosubstantially close communication between the interior of barrel 4 andbore 84 in this position.

Referring now to FIG. 2, the operation of the gun is initiated withactuation of the trigger and sear assembly as outlined above. As hammer6 moves forward, bore 84 and aperture 86 move forward displacing theshot 80a located therein forwardly past the end of enlarged sphericalportion 68 and allowing the shot to drop into barrel 4. Another shot,80!), then drops into the vacated aperture 82 in the bottom of shotchamber 76. The position assumed by shot 8%, prevents shots remaining inshot chamber '76 forward of the aperture from rolling to the rear of thechamber when the muzzle is elevated and visa versa where the muzzle isdepressed. As is shown in FIG.

M 2, faces 52 and 54 of the trigger and sear respectively converge onone another as the sear moves hammer 6 and barrel 4 towards itsforwardmost position against the compressive force of spring 38.

Aperture 82 may be either circular in configuration as shown, or maytake the form of an elongated slot parallel with the axis of chamber 76.The elongated slot insures proper feeding of the shot into the apertue84.

Referring now to FIG. 3 of the drawing, trigger 4% is in its rearmostposition, faces 52 and 54 having converged, moving the end of sear 44which engages notch 48 downwardly releasing the hammer and barrelassembly. Hammer 6 has moved rearwardly under the influence of thespring 38 and is about to impact valve assembly to cause a burst ofpressure to be released through the valve as sembly into barrel 4 andstart shot to accelerate out of the barrel.

The operation of valve assembly 8 is shown in FIG. 4. This figure showsthe assembly in the impacted, open condition. Hammer 6 contacts shoulder64, the impact energy of the hammer causing valve stem 62 to bedisplaced rearwardly. Since the rearward end of tube 66 of the valvestem 62 is in contact with the face of recessed portion '72 of valveseat 56, the rearward movement of the valve stem also displaces thevalve seat rearwardly against the pressure in chamber 10. Although seat56 is slidably fitted within expansion chamber 1%, the fit issufficiently loose to allow pressure from the interior of chamber 10 toescape therearound as shown by the arrows. The sealing effect of seat 56is achieved through biased contact of the forward annular face 88thereof with the rearward face of seal 58. Rearward displacement of seat56 breaks the seal between face 88 and seal 58 allowing pressure fromchamber 19 to pass therebetween through bores 74 in tube 66 and thenceinto the interior of barrel 4. After hammer 6 has expended kineticenergy, the pressure in chamber 10 combined with the force of spring 70is of sufiicient magnitude as described above to reposition seat 56against the seal 58 thereby terminating the flow of gas therebetween.

Upon release of trigger 4t], spring 46 returns the trigger and searassembly to the initial position and the elements of the device assumethe position shown in FIG. 1.

The device may also be furnished with a secondary sear structure such asthat shown generally at 90. The structure comprises a pivotally-mountedsecondary sear 92 disposed in housing 2 which is spring loaded in anupward direction by spring 94 and which is engageable with notch 48 inhammer 6 when the hammer and barrel assembly are displaced forward ofthe normal operating position as shown in FIG. 6. Suitable means such asbolt-like extension 93 (FIG. 5) through slot 95 in the side of housing 2may be furnished to allow displacement of the hammer and barrel assemblyin the forward direction to allow sear 92 to engage notch 48. As will benoted in FIG. 3, the lower front face of scar 44 engages face 96 ofsecondary sear 92 when the trigger is displaced to an extreme rearwardposition. This provides for release of the hammer and barrel assemblyfrom the secondary sear engaging position by a camming action betweensear 44 and safety sear face 96. The incorporation of the secondary searmechanism provides a single shot, manually cocked capability, wheredesired, allowing the gun to be fired with a minimum of trigger force.This feature is of particular utility in target shooting.

Of course the mechanism as hereinabove described for incorporation in apistol could obviously be incorporated in a rifle frame or the likewithout changing the theory of the invention. Furthermore, the sphericalprojectiles shown do not constitute a necessary element of theinvention, and pellets, darts or any like projectiles could besubstituted without effecting the operation of the device.

The materials used in the fabrication of the gun are largely a matter ofchoice and convenience although portions such as the hammer member arepreferably fabri- 'cated of high-density material such as brass or thelike to provide sufficient kinetic energy yet keep the member compact,making the member operate the valve mechanism as described. Obviouslythe sealing members such as the valve seat and seal should be fabricatedof some suitable elastomeric material such as rubber to provide theproper scaling properties for the parts.

Preferably the elastomeric material should be sufficiently soft as toprovide easy sliding and to allow small particles which may be presentin the valve area to embed themselves without causing leakage. The sealshould also be sufficiently thin, on the order of .050 inch for example,to avoid extrusion around the valve seat and also to prevent the sealfrom following the seat through expansion, when the seat is displacedfrom the seal.

Gbviously many modifications and variations of the present invention arepossible in the light of the above teachings. It is therefore to beunderstood that, within the scope of the appended claims, the inventionmay be practiced otherwise than as specifically described.

I claim:

1. A gas-powered gun comprising: a frame having a handle thereon; aprojectile barrel slidably mounted in said frame and axiallyreciprocable between a forward and a rearward position therein, saidbarrel having a breach end; an annular hammer coaxially mounted on thebreach end of said barrel and reciprocable therewith; a pressurized gascapsule disposed in said handle; an expansion chamber adjacent to thebreach end of said barrel; means including a puncturing device toconnect the pressure in said gas capsule to the interior of saidchamber; means including a conduit to connect said chamber to the boreof said barrel; a valve disposed in said conduit, said'valvebeingreciprocable between a. closed position towards said barrel and anopen position in the opposite direction; said valve being formed to bedisposed in a sealably closed condition by the pressure in said chamber;a first spring disposed in said chamber biasing said valve toward closedposition; a valve stem mounted coaxially in said valve and reciprocabletherewith, said stem engaging said hammer and having an end slidablyprojecting into said barrel; a second spring disposed around said barrelto bias said hammer in a rearward position against said valve stem;means to adjust the bias in said second spring; trigger means toreciprocate said hammer to a forward position and automatically releasesaid hammer for return reciprocation to said rearward position; saidpressure maintaining said valve in a closed position against the staticload of said second spring and said hammer but permitting openingthereof under the dynamic load of said second spring and said hammer assaid hammer reengages said valve stem on return reciprocation thereof; aprojectile storage chamber above said barrel; and means to sequentiallyfeed projectile into said barrel from said storage chamber.

2. A gas-powered gun in accordance with claim 1 wherein saidlast-mentioned means comprises: a projectile transmitting borevertically disposed through the wall of said hammer and communicatingwith the interior of said barrel; a projectile-transmitting aperturevertically disposed through the wall of said storage chamber, said boredisposed to be aligned with a portion of said aperture and with theprojecting end of said valve stem when said hammer is disposed in saidrearward position; whereby a projectile from said storage chamber isgravity fed through said aperture into said bore and retained therein bythe projecting end of said valve stem while said hammer is disposed insaid rearward position and said projectile is gravity fed into saidbarred when said hammer is displaced toward said forward position.

3. A gas-powered gun in accordance with claim 2 wherein said triggermeans comprises: a trigger member having an upper and lower end thereto,said trigger being pivotally mounted at an intermediate portion thereofto said frame; a sear having a forward and arearward end thereto, saidsear being pivotally connected at an intermediate portion thereof to theupper end of said trigger, said sear being reciprocable between arearward and a forward position by pivoting of said trigger between aforward and a rearward position; biasing means disposed to constantlyurge said sear toward said rearward position and the forward end thereofin an upward direction, the forward end of said sear engaging saidhammer for forward reciprocation thereof when said sear is in a rearwardposition and during substantial portion of the forward reciprocationofsaid hammer, the rear end of said sear engaging said trigger as the searnears the forward position there-of, thereby blocking the pivotalconnection between said trigger and said sear to cause withdrawal ofsaid sear from engagement with said hammer by further rearward pivotingof said trigger; the withdrawal of said sear from said hammer therebyautomatically releasing said hammer for return reciprocation by saidsecond spring.

4. In a gas-powered gun, an inertia-operated pressure release systemcomprising: a frame having a cylindrical chamber therein; a cylindricalvalve seat slidably mounted in said chamber for reciprocation therein; apressure source connected to said chamber on one side of said valveseat; an annular seal coaxially disposed on the other side of said valveseat at the mouth of said chamber; means defining a recess coaxiallydisposed in the face of said seat adjacent to said seal; a. valve springmounted in said chamber to bias said seat toward a sealing relationshipagainst said seal; a tubular valve stem disposed through said sealcoaxial therewith and engaging the recess of said seat; means defining aplurality of trans verse bores through said stem adjacent said seat; aflange mounted at an intermediate portion of said stern in spacedrelation to said seal, said frame further having an enlarged borecoaxial with and adjacent to the mouth of said chamber; a projectilebarrel reciprocably mounted in said bore, said projectile barrel beingslidably disposed around the forward portion of said valve stem coaxialtherewith; an annular hammer member coaxially mounted on said barrel andengageable with said flange; a barrel spring urging said hammer towardengagement with said flange, the pressure from said pressure sourceagainst said seat and the force of said valve spring being such thatsaid seat is sealingly engaged with said seal against the static loadimposed by said hammer and said barrel spring through said valve stem;means to reciprocate said hammer away from said valve stem and releasesaid hammer for re-engagernent with said flange under the influence ofsaid barrel spring, the kinetic energy in said hammer being such thatengagement with said flange overcomes the pressure from said source andthe force of said valve spring and displaces said valve stem rearwardlyto displace said seat from said seal to release a burst of gas pressuretherebetween through the bore of said stem into said barrel.

5. A gas powered gun comprising:

a frame;

a projectile barrel slidably mounted in same said frame and axiallymovable between a forward cocked position and a rearward positiontherein;

a source of gas pressure, means including a valve for controllablyconnecting said source of pressure to the bore of said barrel, saidvalve being movable between a closed position towards said barrel and anopen position in the opposite direction;

a first biasing means including pressure from said source for constantlyurging said valve toward the closed position;

a second biasing means constantly urging said barrel toward said valve;

a trigger member pivotally mounted on said frame for movement between aforward and rearward location, a sear means pivotally mounted to saidtrigger,

said sear means engaging said barrel to move said barrel to said forwardcocked position when said trigger is moved toward a rearward location,means to withdraw said sear means from engagement with said barrel whensaid trigger reaches said rearward location to release said barrel forreturn movement to said rearward position under the influence of saidsecond biasing means;

said first biasing means maintaining said valve in a closed positionagainst the static load of said second biasing means and said barrel butpermitting opening thereof under the dynamic load of said second biasingmeans and said barrel as said barrel re-engages said valve on returnmovement thereof;

and means to feed projectiles to said barrel.

6. A gas powered gun comprising:

a frame;

a projectile barrel slidably mounted in said frame and axially movablebetween a forward cocked position and a rearward position therein, saidbarrel having a breech end;

an annular hammer mounted on the beech end of said barrel and movabletherewith;

a source of gas pressure;

a chamber communicating with said source of pressure coaxially disposedwith respect to said barrel;

a conduit between said chamber and said barrel for conveying pressuretherebetween;

a valve mounted in said conduit and axially movable between a closedposition towards said barrel and an open position in an oppositedirection;

said valve being formed to be disposed in a sealably closed condition bythe pressure in said chamber;

a first spring means mounted in said chamber disposed to urge said valvetoward said barrel;

a hammer-engaging valve actuator coaxially connected to said valve andmovable therewith;

a spring means biasing said hammer toward a rearward position againstsaid valve actuator;

a trigger member pivotally mounted on said frame for movement between aforward and a rearward location, a sear means pivotally mounted to saidtrigger, said sear means pivotally moving with respect to said triggerand simultaneously moving between a rearward and a forward configurationwhen said trigger is moved toward said rearward location, said searmeans engaging said hammer in said rearward configuration and during asubstantial portion of the movement thereof to move said hammer and saidbarrel to said forward cocked position when said trigger is movedtowards said rearward location, means on said trigger adapted to engagesaid sear means to terminate pivotal movement therebetween proximatesaid rearward location to provide withdrawal of said sear means fromengagement with said hammer when said trigger reaches said rearwardlocation to thereby release said hammer for return movement to saidrearward position under the influence of said second spring, and meansto bias said trigger in said forward location and said sear means towardengagement with said hammer;

said pressure maintaining said valve in a closed position against thestatic load of said second spring and said hammer but permitting openingthereof under the dynamic load of said second spring and said hammer assaid hammer re-engages said actuator on return movement thereof;

a tubular projectile storage chamber disposed in parallel relationshipabove said barrel;

and means including a valve to sequentially feed projectiles into saidbarrel.

References Cited by the Examiner UNITED STATES PATENTS FOREIGN PATENTS1907 Great Britain. 12/60 Germany.

RICHARD C. PINKHAM, Primary Examiner.

LOUIS R. PRINCE, Examiner.

1. A GAS-POWERED GUN COMPRISING: A FRAME HAVING A HANDLE THEREON; APROJECTILE BARREL SLIDABLY MOUNTED IN SAID FRAME AND AXIALLYRECIPROCABLE BETWEEN A FORWARD AND A REARWARD POSITION THEREIN, SAIDBARREL HAVING A BREACH END; AN ANNULAR HAMMER COAXIALLY MOUNTED ON THEBREACH END OF SAID BARREL AND RECIPROCABLE THEREWITH; A PRESSURIZED GASCAPSULE DISPOSED IN SAID HANDLE; AND EXPANSION CHAMBER ADJACENT TO THEBREACH END OF SAID BARREL; MEANS INCLUDING A PUNCTURING DEVICE TOCONNECT THE PRESSURE IN SAID GAS CAPSULE TO THE INTERIOR OF SAIDCHAMBER; MEANS INCLUDING A CONDUIT TO CONNECT SAID CHAMBER TO THE BOREOF SAID BARREL; A VALVE DISPOSED IN SAID CONDUIT, SAID VALVE BEINGRECIPROCABLE BETWEEN A CLOSED POSITION TOWARDS SAID BARREL AND AN OPENPOSITION IN THE OPPOSITE DIRECTION; SAID VALVE BEING FORMED TO BEDISPOSED IN A SEALABLY CLOSED CONDITION BY THE PRESSURE IN SAID CHAMBER;A FIRST SPRING DISPOSED IN SAID CHAMBER BIASING SAID VALVE TOWARD CLOSEDPOSITION; A VALVE STEM MOUNTED COAXIALLY IN SAID VALVE AND RECIPROCABLETHEREWITH, SAID STEM ENGAGING SAID HAMMER AND HAVING AN END SLIDABLYPROJECTING INTO SAID BARREL; A SECOND SPRING DISPOSED AROUND SAID BARRELTO BIAS SAID HAMMER IN A REARWARD POSITION AGAINST SAID VALVE STEM;